A hydroxynorephedrine derivative represented by the following formula (II):
has been reported as having an excellent β3-adrenaline receptor stimulating effect and being a useful compound as a therapeutic agent for pollakiuria or urinary incontinence (see Patent reference 1).
Heretofore, as a crystalline hydroxynorephedrine derivative hydrochloride represented by the above formula (I), crystalline forms A and B have been reported (see Patent reference 2).
Particularly, crystals represented by the above formula (I) wherein the diffraction pattern by the powder X-ray diffractometry shows characteristic peaks at diffraction angles (2θ) of 8.9, 10.2, 12.9, 14.2, 15.6, 18.4 and 20.6 (crystalline form A) and the diffraction pattern by the powder X-ray diffractometry shows characteristic peaks at diffraction angles (2θ) of 7.3, 10.1, 12.2, 14.6, 15.9, 16.0, 18.7 and 21.8 (crystalline form B) have been reported. However, from the diffraction chart by the powder X-ray diffractometry, crystals of the hydroxynorephedrine derivative hydrochloride of the present invention are novel crystal polymorphs which are different from these crystals.
Patent reference 1: International Publication No. WO00/02846 pamphlet
Patent reference 2: International Publication No. WO03/024916 pamphlet